The present invention relates to instrumentation, implants, and techniques for orthopedic surgery and, more particularly, to a transosseous core approach for joint repair, replacement, and/or treatment, wherein the treatment site is approached through a transosseous pathway constructed by taking a bone core out of a bone, at the joint.
An orthopedic surgeon may wish to gain entry to a particular joint for multiple reasons. The surgeon may wish to alter or remove a defect in the joint, to replace an articular surface of the joint or the entire joint (i.e., total joint arthroplasty), to transplant cartilage autographs/implants and/or to alter the characteristics of soft tissues in and around the joint such as tendons, ligaments, joint capsule, etc. In a typical joint, the articular surfaces of the joint are surrounded by soft tissue structures, injury to which is often undesirable or at least to be minimized. FIG. 1 schematically illustrates a typical joint (representative of diarthroses) and surrounding anatomical structures of the joint. The exemplary joint includes first bone xe2x80x9cAxe2x80x9d and second bone xe2x80x9cBxe2x80x9d, each including the articular surface 1A, 1B comprising articular cartilage enclosed within a synovial lining 2. Articular surfaces 1A, 1B and synovial lining 2 are in turn surrounded by a joint capsule 3 on which a bursa 5 may be disposed. The synovial lining is also referred to as the synovial stratum, which together with the fibrous stratum, make up the articular capsule. Bones A, and B are attached to tendon 6 and muscle 7 and are coupled to each other by ligaments 4. Blood vessels and nerves (not shown) generally run with muscle 7, tendon 6, and/or ligaments 4. Each bone A, B includes portions of non-articular surface 8A, 8B outside joint capsule 3 that are substantially clear of the above-mentioned soft tissue structures of the joint.
Conventional methods for gaining access into the joints typically require wide exposures and joint dislocation. See for example U.S. Pat. No. 4,550,450, entitled xe2x80x9cTotal Shoulder Prosthesis System,xe2x80x9d and U.S. Pat. No. 5,507,833, entitled xe2x80x9cHip Replacement and Method for Implanting The Same.xe2x80x9d These classical wide exposures damage large area of tissue, create large scars, jeopardize neurovascular structures, produce considerable blood loss, increase the potential for other significant complications, and increase the risk of infection. Wide exposures, because of their inherent nature, traumatize tissues as they are cut, retracted, and/or divided. The amount of tissue disrupted increases the healing time and the physiological strain on the patient because the amount and severity of postoperative pain correlate directly to the size of the incision and extent of surgery. Traditional wide exposures can also create limits on the functional results of surgery to treat joint problems by the sequlae introduced by the exposure itself. More recent developments in arthroscopic techniques may reduce the amount of trauma to which a patient may be subjected, but many procedures are not amenable to arthroscopic techniques and frequently such procedures still entail damage to soft tissue structures surrounding the joint such as the articular capsule.
Patient cooperation is an important factor in postoperative rehabilitation. The ultimate result of the treatment of joint problems hinges to a major degree on this fact. Postoperative pain which is proportional to the incision size, exposure, and/or tissue damage, inhibits the rate of patient""s rehabilitation. The inability to reach desired rehabilitation goals often results in an overall inferior and/or an unsatisfactory result. These additional drawbacks of conventional joint surgical exposures and treatments contribute to reduce the ultimate outcome of the surgical intervention, often introducing unwanted and unnecessary sequlae.
In the present invention, a joint is entered via a route passing through a pathway provided in a portion of a joint bone. Such pathway is made by taking out a bone core from the bone in or adjacent to the joint without substantially compromising physical integrity and physiological viability of the joint. Typically the main route for the present invention traverses through a more-accessible bone of the joint which can be aligned with a less-accessible bone of the joint to facilitate treatment of the articular surfaces and/or other structures in the joint.
The present invention thus provides a new method and instrumentation for gaining access to areas in and around the joint surfaces to treat problems of the joint as well as to provide new implants and instrumentation adapted for the new method. The transosseous core approach of the present invention has at least two main advantages over conventional surgical exposures. A first is that the present invention requires substantially smaller incisions than standard exposures. A second is that the present invention does not substantially interfere with normal anatomical structures surrounding the joint such as vascular, nervous, muscular, ligamentous, and other soft tissues of the joint and, therefore, is less invasive. Additionally, in many cases the exposure obtained by the transosseous core approach provides better and more direct access to areas of the joint not found in current exposures.
Every joint includes at least two bones arranged to allow movement thereof. Each bone includes an articular surface substantially enclosed within a joint capsule and a non-articular surface (e.g., a superficial portion thereof) disposed substantially outside the joint capsule. The present invention is based on the transosseous core approach where the articular surface of the bone and other tissues within the joint capsule can be accessed through a pathway (such as the hole) in the bone commencing from its non-articular surface and approaching its articular surface.
Accordingly, in one aspect of the present invention, a method may be provided to treat the joint by positioning the first bone with respect to the second bone, by removing a bone core from the first bone along a first axis to provide a bone core hole beginning in a first region of the first bone and approaching the first articular surface of the first bone without penetrating its articular surface wherein the first region is its non-articular surface, by performing an intervention through the bone core hole, and by replacing at least portion of the first bone core within the bone core hole. Such intervention may be implanting at least one component of a prosthetic device within the first bone core hole.
Alternatively, the method may be provided for treating the joint by positioning the first bone with respect to the second bone, by cutting the first bone starting from its first region (e.g., the first non-articular surface thereof) and approaching its first articular surface, and by ceasing cutting at a point adjacent the first articular surface without penetrating it, thereby providing the first bone with an elongated first core hole capable of receiving an implant. The first region is generally the first non-articular surface of the first bone and, preferably, superficial to a surface of a body part such as limbs.
In another aspect of the invention, an access is provided to the joint including at least one more-accessible bone, at least one less-accessible bone, and the surrounding anatomical structures by positioning the more-accessible bone with respect to the less-accessible bone, by cutting the more-accessible bone starting from a first region and approaching its articular surface, wherein the first region is its non-articular surface, and by ceasing cutting at a point adjacent the articular surface of the more-accessible bone without penetrating it. Accordingly, the more-accessible bone is provided with a more-accessible core hole providing the access to a portion of the more-accessible bone which is substantially proximate to its articular surface.
In the alternative, a method may also be provided for an access to the joint by positioning the first bone with respect to the second bone, cutting out a core portion of the first bone starting from the first non-articular surface of the first bone and approaching the first articular surface of the first bone, where the core portion of the first bone is not coupled to the surrounding anatomical structures of the joint, and by ceasing cutting at a point adjacent the first articular surface of the first bone without penetrating it. Therefore, without detaching the surrounding anatomical structures from the first bone, the first bone can be provided with a first core hole configured to receive an implant.
In yet another aspect of the invention, a method for providing an access to the joint by positioning the first bone with respect to the second bone, by incising at most a portion of the joint capsule, by cutting out a core portion of the first bone starting from an exterior portion of the first bone and approaching an interior portion of the first bone, and ceasing cutting at a point of the first bone disposed inside the joint capsule. Thus, without substantially compromising integrity of the joint capsule, the first core hole can be provided to the first bone. A skin, fascia, fat layer, and/or soft tissues disposed on or adjacent the exposed portion of the first bone may be incised and a muscle may be divided in a direction of its main fibers. Blood vessels and nerves may also be disposed away from the exposed portion of the first bone.
In another aspect of the invention, a method is provided for treating a joint by positioning the first bone with respect to the second bone, by cutting a hole in the first bone along a first axis beginning in the first bone first region and passing through the first bone articular surface, by continuing cutting the hole through the second bone articular surface and into the second bone, by terminating cutting of the hole within the second bone, and by implanting at least one component of a prosthetic device within the second bone hole by passing the component through the first bone hole.
In a further aspect, another method is provided for treating a joint by positioning the first bone with respect to the second bone, by cutting a hole having a first diameter in the first bone along a first axis beginning in the first bone first region and passing through the first bone articular surface, by continuing cutting the hole through the second bone articular surface and into the second bone, by enlarging the hole to a second diameter greater than the first diameter at a location spaced away from the first bone first region, and by implanting at least one component of a prosthetic device within the enlarged hole by passing the component through the hole with the first diameter.
The present invention further provides various orthopedic implants (including implant assemblies and modules thereof) for the transosseous core method and devices therefor.
In one aspect of the invention, an orthopedic implant assembly is provided which is arranged to be implanted adjacent to or in the joint through a pathway formed inside the joint bone and having an effective pathway dimension. Such implant assembly includes at least two implant modules each of which is configured to have an effective module dimension no greater than the effective pathway dimension so as to allow passage of the implant module through the pathway. Each implant module is configured to couple with at least one of the others to form the implant assembly in situ having an effective assembly dimension which is no less than both of the effective pathway dimension and effective module dimension.
In another aspect, a surgical kit is provided to include a bone cutting tool having a cutting element for creating a bone hole of a first diameter, and a bone prosthesis assembly with at least two implant modules configured and dimensioned to be separately inserted through the bone hole of the first diameter and to mate together at a site of interest to form said assembly. The surgical kit also includes a surgical hemostat for treating the wall of the bone hole. The hemostat comprises an applicator expandable from a retracted position to a expanded position, a cylindrical, expandable sleeve configured and dimensioned to be disposed over the applicator in the retracted position, and a hemostatic agent disposed on the sleeve, where expansion of the applicator to the expanded position within a bone hole forces the hemostatic agent against the wall. The surgical kit further includes a cartilage punch having an operative portion configured and dimensioned to be inserted through the first diameter bone hole and manipulated from outside the hole, where the operative portion typically includes a blade which surrounds a central cavity to capture cartilage cut by said blade. The surgical kit may further includes a second bone cutting tool with an operative portion configured and dimensioned to be inserted through the first diameter bone hole and manipulated from outside the hole, where the operative portion includes at least one cutting member for removing bone material to provide a larger void within the first diameter bone hole.
In another aspect, a prosthetic assembly is provided to be inserted through a bone hole having a first hole diameter and implanted at a site of interest within a bone or joint. The assembly includes at least two implant modules configured and dimensioned to be individually inserted through the bone hole and the implant modules fit together at the site of interest to form said prosthetic assembly. When assembled, the assembly has at least one dimension larger that the first hole diameter.
In a further aspect, a modular, prosthetic finger joint assembly is provided. The assembly is adapted to be inserted through a bone hole, wherein said bone hole extends from a first finger bone through the first bone articular head and through an articular surface of a second finger bone. The assembly comprises: an articular head module, having a convex articular surface and configured for attachment to the first bone through said bone hole; and an articular base module, having a concave articular surface for mating with said convex articular surface, said base module being configured and dimensioned to be inserted through said bone hole and attached to the second bone.
In another aspect in accordance with the invention, a transosseous core method for implanting a finger joint prosthesis is provided. The method comprises: forming a hole through the articular head of a first finger bone transverse to the length of the first bone and through the articular surface of a second finger bone to expose the intramedullary canal of the second bone and expose the intramedullary canal of the first bone; removing a portion of the articular surface of the first bone; inserting a first rod through the first bone hole and into the first bone intramedullary canal; inserting a second rod through the first bone hole and into the second bone intramedullary canal; attaching a base articular module onto the end of the second rod module; and attaching an articular head module onto the end of the first rod module to engage the two articular surfaces.
In a further aspect, in accordance with the invention, a transosseous core method for implanting a finger joint prosthesis is provided. The method comprises: forming a hole in the articular head of a first finger bone transverse to the length of the bone and further through an articular surface of a second, cooperating finger bone; removing a portion of the articular head of the first bone; implanting a base articular module onto the end of the second bone, said base module having a concave articular surface; and implanting an articular head module onto the end of the first bone, said head module having a convex articular surface, wherein said base and head modules are configured and disposed to engage their articular surfaces.
In another aspect, a surgical tool is also provided for cutting bone and includes an elongated body and a cutting member. The elongated body has a longitudinal axis and defining an opening in a distal portion thereof and the cutting member is movably disposed within the body so that the cutting member moves between a first position disposed within the body and a second position extending out of the opening for cutting bone.
In another aspect, a surgical hemostat is provided for treating walls of bone holes. Such hemostat typically includes an applicator expandable from a retracted position to a expanded position, a cylindrical, expandable sleeve configured and dimensioned to be disposed over the applicator in the retracted position, and a hemostatic agent disposed on an outer surface of the sleeve. When the applicator is expanded to the expanded position within a bone hole, the hemostatic agent is forced against the bone hole wall.
In a further aspect, an expandable surgical bone reamer includes a central member, a plurality of arms extending radially from the central member where the arms are extensible in the radial direction between retracted and expanded positions, a bone reaming member disposed on each arm opposite the central member, and an expansion mechanism operatively connected to the arms such that the distance of the bone reaming members from said central member may be controlled.
Other features and advantages of the present invention will be apparent from the following detailed description, and from the claims.